Foundries use molds, such as sand molds, investment molds, etc., to produce metal and other material castings having a great variety of sizes, shapes, and complexities. Some castings, such as those for valve bodies, have very unique shapes that require a high level of quality to be maintained. To better control the casting process and maintain a high level of quality, chills can be utilized in the molds to more rapidly cool molten metal, which is commonly done to minimize or eliminate shrink defects in all types of metal castings. A typical chill is a piece of metal, or other acceptable material, that is incorporated into a mold body at the edge of the molding cavity and forms a part of the molding cavity in the area where accelerated cooling of the casting is desired. The chill is incorporated into the mold body when the mold body is produced.
However, various issues arise in an attempt to incorporate typical chills in mold bodies created using 3D printing, such as 3D sand printing. In 3D sand printing, a 3-dimensional design of the entire mold or of a particular mold body is produced and divided into multiple layers. A thin layer of sand, such as silica sand, which could be mixed with a suitable activator, is then laid down representing the first layer of the design. A binder is the applied to the areas required to form the solid structure for that particular layer. A second thin layer of sand, representing the second layer of the design, is then laid down over the first layer and the binder is applied to the areas required to form the solid structure for that particular layer. This continues layer after layer to form the completed mold or mold body design.
Using this 3D sand printing process, the mold body can no longer be produced around a typical chill, as placement of the chill would impede the machinery used in the 3D sand printing process. Thus, instead of producing the mold body around the chill, the chill has to be produced outside of the mold body to a near net shape, a cavity has to be formed in the mold body to receive the chill, and the chill has to be inserted into the existing 3D sand printed mold. However, various issues arise such as maintaining the dimensional tolerances of the chill and the cavity formed in the mold body required for the chill to properly fit in the 3D sand printed mold body and to properly align the chill with the desired surface of the casting. In addition, it can be difficult to place and secure the chill within the cavity so that the chill does not move or become dislodged during the casting process.